Fabricated axial flow bladed structures



June 23, 19 59 E. A. STALKER 2,891,719

FABRICATED AXIAL FLOW BLADED STRUCTURES Filed March 2, 1951 2 Sheets-Sheet 1 4' III/11111111,;

INVENTOR. 5 2 awed/15 June 23, 1959. E. A. STALKER 2,391,719

FABRICATED AXIAL FLOW BLADED STRUCTURES Filed March 2, 1951 2 Sheets-Sheet 2 IN V EN TOR.

United States Patent flice 21 9 1 Patented June 23,1959

FABRICATED AXIAL FLOW BLADED STRUCTURES Edward A. Stalker, Bay City, Mich., assignor to The Stalker Corporation, a corporation of Michigan Application March 2, 1951, Serial No. 213,596 11 Claims. (Cl. 230-134) My invention relates to bladed axial flow structures adapted to interchange a force with a fluid, such as for instance, in compressors and turbines.

An object of the invention is to provide a rotor structure which can be fabricated of thin sheet metal in subassemblies which can be fixed together with a minimum of fixtures.

Another object is to provide a rotor structure wherein the strength-significant joints are visible for inspection.

Still another object is to provide a rotor structure whose subassemblies can be readily spot-welded to fix the pieces together properly for brazing.

Other objects will appear from the specifications, drawings and claims.

The above objects are accomplished by the means illustrated in the accompanying drawings in which Fig. 1 is a fragmentary axial View of a bladed rotor according to this invention;

Fig. 2 is a fragmentary axial section through the rotor of Fig. 1;

Fig. 3 is a section through a blade along line 3-3 in Fig. 1;

Fig. 4 is an elevation of a rotor web shown isolated from the rotor;

Fig. 5 is a cross section of the web along line 55 in Fig. 4;

Fig. 6 is a fragmentary radial view of rim or fairing segments showing the cutouts for the blades;

Fig. 7 is a fragmentary section along lines 7-7 in Fig. 6;

Fig. 8 shows the rotor supported in the fixture for brazing; and

Fig. 9 is an end view of a blade fixture as seen from 9-9 in Fig. 8.

This invention differs from my copending application Serial No. 213,595, filed March 2, 1951, in that the side plates carry the blade stems. Also the side plates diverge radially inward which makes the structure sounder in strength even though the web member is secured only to one plate. A special means is also provided for securing the inner ends of the web flanges to the hub structure at the inner ends of the web members and plates.

Referring now to the drawings the rotor is indicated generally by 10. It comprises the hub 12, the clutch elements 14 and 16 by means of which torque may be transmitted through successive stages, and plate assemblies 20 and 22 and the blade structure 26. The blades are peripherially spaced about the complete perimeter of the rotor.

The individual blades 26 each comprise an envelope 28 fixed to a pair of stems 30 and 31. See Figs. 1-3. The stems 30 are fixed to the hub plate 34 while the stems 31 are fixed to the hub plate 36. Each stem of one plate sligns chordwise with a stem of the other plate forming stem sets or pairs. The disks or plates 34 and 36 diverge toward the hub to provide a structure adapted to resist axial load. The disks are fixed between the hub 12 and the clutch elements 14 and 16 as shown par- 2 ticularly in Fig. 2, preferably by fusion of the radiall inner parts or ends 34a and 36a thereof as by welding or brazing.

The assembly 22 comprises the rearward plate 36, the Web 40 which has two flanges 42 and 44, shown in Figs. 2, 4 and 5. The flange 44 is spot-welded to the plate 36 at several spots 48. Flange 42 has a radially inwardly extending portion 42a which is received between clutch element 14 and hub 12 and secured to the latter. The blade stem 31 is also spot-welded to plate 36 at spots 50. The fairing segments 52 and the angle ring 54 are spot-welded together and the fairing is spot-welded to plate 36 at spots 56.

The complementary plate assembly 20 comprises the forward plate 34 and is similar to plate assembly 22 except that there is no web member 40 attached thereto. Fairing segments 53 are spot welded to hub plate 34 and angle ring 54 is spot welded to the several segments. As shown, the fairing segments diverge outwardly away from the hub in the opposite direction to the inclination of the hub plates 34, 36. The flange portions 64, 66, respectively, are formed with slots 57 corresponding to the shape of the adjacent portions of the blades, and the flanges are bent into interfitting contact with each other forming a continuous closed surface extending peripherally between successive blades and axially from the inlet to the exit side of the rotor. This assembly 20 complements the assembly 22 to comprise the rotor.

By providing the plate assemblies as described both sides of the sheet metal parts are accessible for spotwelding. The spots serve two important purposes. First they locate and hold the parts in place so that fixtures or jigs for this purpose are eliminated. Secondly they hold the flanges and other faying surfaces closely together so that brazing material will flow by capillary action into the joints between the parts to be fused together by brazing; For certainty of a good brazed joint, the gap between pieces should not exceed about three thousandths of an inch.

In making the rotor assembly the two plate assemblies 20 and 22 are placed in axial alignment with stems aligned chordwise to receive the blade envelopes over each pair or set of stems.

The lower ends of the flanges 42 and the hub plates 34 and 36 are between the hub and the clutch elements as shown in Fig. 2. The teeth 60 are not yet cut in the clutch elements so that these parts may be resistance welded together.

In the course of the rotor or final assembly, brazing material preferably in the form of a paste is placed at all joints and on surfaces to be brazed. The assembly is then heated in a furnace so that the molten braze material will fuse the parts together.

The joint between the flanges 42 and the plate 34 is not relied upon for strength since the plate 36 and web 40 are strong nough to take the axial loadwhere the lower end of 42 is fixed to the hub 12 as described above. If desired brazing material may be placed along the joint of 42 and whatever joining occurs will be so much additional strength, but the amount of fused surface that will be obtained is not assured since the flange when heated may warp away from the plate. This joint is not relied upon since it cannot be inspected visually and no spot welds are readily provided to give the certainty of fusing which should be present in the absence of visual inspection. 7

The teeth 60 are cut after the brazing operation.

It will be observed from Fig. 2 that the plates 34 and 36 support the flanges 66 and 64 of the parts 52 and 53 with said flanges directed axially and adapted for joining one to the other so that a smooth joint 68 can be made by pressing the flanges against the plate, and for fitting --about the blade envelopes at the root ends thereof to close the rotor between blades.

It will also be observed from Fig. 1 that the segments 52 constitute small fractions of the periphery so that these parts can be made by stamping with dies.

Preferably the parts 55 and 54 are complete rings since they will then reinforce the segments 52 and 53 and carry stress across joints in the parts 52 and 53.

Fig. 6 shows the cut-outs 57 in the flanges 64 and 66 of the fairing segments as seen looking radially inward from the blade tips.

As shown in Fig. 7 corner pieces 70 may be used to reinforce the fairing segments 53 and 54 at localities between blades.

Fig. 8 shows the rotor assembly support in the fixture '80 comprising the bed plate 82, the blade fixtures 8385 and the cup 86. Only two blades are shown on the rotor for clearness and simplicity of exposition.

The blade fixtures as shown in Fig. 9 comprise a base 90 and a heavy movable element 92 which, by its weight,

presses the blade against the stem within. The fixture also holds the blade at the correct pitch angle.

The cup 86 serves to press the flanges 64 and 66 against the outer ends of the plates 34 and 36.

While I have illustrated specific forms of the invention, it is to be understood that variations may be made there in and that I intend to claim my invention broadly as indicated by the appended claims.

What is claimed is:

1. In combination in an axial flow bladed rotor adapted to interchange force with a fluid, a hub, a plate assembly comprising a plate, a plurality of radially directed webs fixed to said plate and to said hub and spaced peripherally about said hub, a plurality of blade stems fixed to said plate in peripherally spaced relation and extendin radiall outward therefrom and rim fairirn segg Y c:

mentary assembly between said stems, said complementary plate assembly being disposed in axial proximity to the first said assembly with said stems of opposite said plates forming pairs aligned ehordwise of the blades, a plurality of blade envelopes each enclosing a said pair of said stems, said envelopes being fused to their respective said pairs of stems to fix said pairs together, said fairing segments having axially directed flanges adapted for joining one to the other and for fitting about said blade envelopes at the root ends thereof to close said rotor between blades, and means fixing said plates to said hub.

2. In combination in an axial flow bladed rotor adapted to interchange force with a fluid, a hub, a plate assembly comprising a plate, a plurality of radially directed Webs fixed to said plate and to said hub and spaced peripherally about said hub, a plurality of blade stems fixed to said plate in peripherally spaced relation and extending radially outward therefrom, and rim fairing segments fixed in said assembly between said stems, a complementary plate assembly comprising a plate, and a plurality of blade stems fixed to the last said plate in peripherally spaced relation and extending radially outward therefrom, rim fairing segments fixed in said complementary assembly between said stems, said complementary plate assembly being disposed in axial proximity to the first said assembly with said stems of opposite said plates forming pairs aligned ehordwise of the blades, a plurality of blade envelopes each enclosing a said pair of said stems, said envelopes being fused to their respective said pairs of stems to fix said pairs together, said fairing segments having axially directed flanges adapted for joining one to the other and for fitting about said blade envelopes at the root ends thereof to close said rotor between .5} blades, each said web increasing in axial width toward said hub to provide strength against axial loads, and means fixing said plates to said hub.

3. In combination in an axial flow bladed rotor adapted to interchange force with a fluid, a hub means, a first plate assembly comprising a hub plate, a plurality of radially directed webs fixed to said plate over a substantial radial extent thereof and spaced peripherally about said hub, a group of blade stems each having a surface of substantial extent overlapping and fixed to said plate in peripherally spaced relation and extending radially outward therefrom, and a complementary plate assembly comprising a hub plate, another group of blade stems each having a surface of substantial extent overlapping and fixed to the last said plate in peripherally spaced relation and extending outward therefrom, said complementary plate assembly being disposed in axial proximity to the first said assembly with said stems of opposite said plates forming pairs aligned ehordwise of the blades and a plurality of blade envelopes each enclosing a said pair of said stems, said envelopes being fused to their respective said stems to fix said pairs together, said plates being fixed to said hub means.

4. In combination in an axial flow bladed rotor adapted to interchange force with a fluid, a hub means, a first plate assembly comprising a hub plate, a plurality of radially directed webs fixed to said plate and spaced peripherally about said hub, a group of blade stems each having a fiat surface fixed to said plate in peripherally spaced relation and extending radially outward therefrom, and a complementary plate assembly comprising a hub plate, another group of blade stems each having a flat surface fixed to the last said plate in peripherally spaced relation and extending outward therefrom, said complementary plate assembly being disposed in axial proximity to the first said assembly with said stems of opposite said plates forming aligned ehordwise pairs of the blades, and a plurality of blade envelopes each enclosing a said pair of said stems, said envelopes being fixed to their respective said stems to fix said pairs together, said plates being fixed to said hub means and said webs being secured to said first plate assembly over a substantial part of the radial extent thereof.

5. In combination in an axial flow bladed rotor adapted to interchange force with a fluid, a forward hub plate having a plurality of peripherally spaced blade stems projecting radially therefrom, a rear ward hub plate having another plurality of peripherally spaced blade stems projecting radially therefrom, each stem of said forward plate being in alignment ehordwise of the blades with a stem of said rearward plate to make a stem set, a hollow blade envelope enclosing each said set and fixed thereto to define a plurality of separate blades, a plurality of radially directed web members peripherally spaced and fixed to one of said hub plates, said web members being disposed between said forward and rearward hub plates, said web members each increasing in width toward the rotor axis and being secured to said first plate assembly over a substantial part of the radial extent thereof, and hub means to fix the radially inward ends of said plates in axial alignment.

6. In combination in a bladed rotor adapted to interchange force with a fluid, a hub means, a pair of hub plates secured to said hub means and extending outwardly therefrom, separate groups of blade stems each having surface contact with one of said hub plates and being secured to the radially outer portions thereof, the stems of one of said groups being arranged in alignment chordwise of the blades with the stems of the other said group forming a plurality of stem pairs, a blade envelope enclosing and bonded to each of said stem pairs, a plurality of separate radially directed web members peripherally spaced and located between said hub plates, means for bonding each of said web members along at least one side thereof to one of said hub plates, and means for fixing the radially inner portions of said web members to said hub means.

7. In combination in a bladed rotor adapted to interchange (force with a fluid, a hub means, a pair of hub plates secured to said hub means and extending outwardly therefrom, separate groups of blade stems each having surface contact with one of said hub plates and being secured to the radially outer portions thereof, the stems of one of said groups being arranged in alignment chord- Wise of the blades with the stems of the other said group forming a plurality of stem pairs, a blade envelope enclosing and bonded to each of said stem pairs, a plurality of separate radially directed web members peripherally spaced and located between said hub plates for stiffening said rotor against axial forces, and fairing segments secured to opposite said hub plates and having flanges (forming a continuous closed surface extending peripherally between the blades and axially from the inlet to the exit side of the rotor.

8. The combination of claim 7 in which said hub plates diverge toward said hub means and said fairing segments diverge away from said hub means.

9. In combination in an axial flow bladed rotor adapted to interchange force with a fluid, a first plate assembly comprising a forward hub plate, a plurality of separate peripherally spaced blade stems secured to said forward hub plate by fused metal and projecting radially outwardly therefrom, a rearward hub plate, a plurality of separate peripherally spaced blade stems secured to said rear hub plate by fused metal and projecting radially outwardly therefrom, each of said blade stems being bonded to its respective hub plate over a substantial area in the generally radial direction, each stem of said forward plate being in alignment chordwise of the blades with a stem of said rearward plate to make a stem set and with the stems of each set being offset relative to the axis of said rotor, a hollow blade envelope enclosing each said set and fixed thereto to define a plurality of blades, and hub means secured to said plates and spaced inward from said blades to hold the inner portions of said plates in axial alignment.

10. In combination in an axial flow bladed rotor adapted to interchange force with a fluid, a plate assembly comprising a forward hub plate having a plurality of peripherally spaced blade stems each overlapping and permanently secured to a flat generally radial surface thereof and projecting radially therefrom, a rearward hub plate having another plurality of peripherally spaced blade stems each overlapping and permanently secured to a fiat generally radial surface thereof and projecting radially therefrom, each stem of said forward hub plate being in alignment chordwise of the blades with a stem of said rearward hub plate to make a stern set, a blade envelope enclosing each said set and fixed thereto to define a plurality of blades, said hub plates diverging along the radii thereof, and means extending over a substantial part of the radial extent of each said plate to fix said plates in said spaced relation.

11. In combination in an axial flow bladed rotor adapted to interchange force with a fluid, a plate assembly comprising a forward hub plate, a plurality of peripherally spaced separate blade stems projecting radially therefrom, a rearward hub plate having a plurality of peripherally spaced separate blade stems projecting radially from said rearward hub plate, each of said stems having surface contact with its respective hub plate over a generally radial surface and being permanently fixed thereto, each stem of said forward hub plate being in alignment chordwise of the blades with a stern of said rearward hub plate to make a stem set, a blade envelope enclosing each said set and fixed thereto to define a plurality of blades, and axially extending fairing means fixed between blades to guide a fluid flow therebetween, said fairing means having flanges turned radially inward and fixed to said hub plates.

References Cited in the file of this patent UNITED STATES PATENTS 648,158 Zoelly Apr. 24, 1900 764,230 Edwards July 5, 1904 874,398 De Ferranti Dec. 24, 1907 1,325,208 Rice Dec. 16, 1919 1,366,119 Darling Jan. 18, 1921 1,417,029 Carlson May 23, 1922 1,641,745 Dimberg Sept. 6, 1927 1,773,349 Bothezat Aug. 19, 1930 1,919,970 Woods July 25, 1933 2,405,190 Darling Aug. 6, 1946 2,497,151 Clark et a1. Feb. 14, 1950 2,501,038 Fransson Mar. 21, 1950 2,553,078 Buck May 15, 1951 2,604,298 Bachle July 22, 1952 2,749,028 Stalker June 5, 1956 FOREIGN PATENTS 596,643 Great Britain Dec. 11, 1947 625,693 Great Britain July 1, 1949 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,891,719 June 23, 1959 Edward A Stalker Column 1, line 68, for "sligns" read aligns column 4, line 19, after "blades" insert a comma; line 37, for "forming aligned chordwise pairs" read forming pairs aligned chordwise' same column 4, line 47, for rear Ward" read rearward lines 53 and 54, for "plurality of separate blades, a plurality of radially" read plurality of blades, a plurality of separate radially Signed and sealed this lst day of December 1959.

SEAL) ttest:

KARL AXLINE ROBERT c. WATSON Attesting Officer Commissioner of Patents 

